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4f78f9fbb0
Since https://reviews.llvm.org/D118118, LLVM will no longer turn CMOVs into branches if it comes from a `select` marked with an `unpredictable` metadata attribute. This PR introduces `core::intrinsics::select_unpredictable` which emits such a `select` and uses it in the implementation of `binary_search_by`.
36 lines
949 B
Rust
36 lines
949 B
Rust
//@ compile-flags: -O
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#![feature(core_intrinsics)]
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#![crate_type = "lib"]
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#[no_mangle]
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pub fn test_int(p: bool, a: u64, b: u64) -> u64 {
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// CHECK-LABEL: define{{.*}} @test_int
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// CHECK: select i1 %p, i64 %a, i64 %b, !unpredictable
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core::intrinsics::select_unpredictable(p, a, b)
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}
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#[no_mangle]
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pub fn test_pair(p: bool, a: (u64, u64), b: (u64, u64)) -> (u64, u64) {
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// CHECK-LABEL: define{{.*}} @test_pair
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// CHECK: select i1 %p, {{.*}}, !unpredictable
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core::intrinsics::select_unpredictable(p, a, b)
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}
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struct Large {
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e: [u64; 100],
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}
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#[no_mangle]
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pub fn test_struct(p: bool, a: Large, b: Large) -> Large {
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// CHECK-LABEL: define{{.*}} @test_struct
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// CHECK: select i1 %p, {{.*}}, !unpredictable
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core::intrinsics::select_unpredictable(p, a, b)
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}
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#[no_mangle]
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pub fn test_zst(p: bool, a: (), b: ()) -> () {
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// CHECK-LABEL: define{{.*}} @test_zst
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core::intrinsics::select_unpredictable(p, a, b)
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}
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